Ex husband and I have 50/50, but he wants to move across country

Me (40F) and my ex-husband (44M) have 50/50 custody of our sons. We were married for 8 years and got divorced 2 years ago. Our sons are 7 and 5. Our oldest has severe autism. To the point where can cannot talk, eat, shower, anything. Doctors are saying he will most likely be non verbal his whole life. He is violent and has been kicked out of 2 schools. Currently we have him in a specialized school and I'm praying that he stays in it. Our younger son has Down Syndrome and is autistic. He is also in special classes. Mentally it has been torture. Whenever I have them, I barely sleep because one of them is having a meltdown. I know everyone says to "embrace the differences", but I am struggling every day so badly. Even when we were married. That was a huge contributer to the divorce.My ex-husband openly expresses how much he wishes he could go back and not have to do this. Internally I think the same thing. I try to have fun on the week I don't have the boys, but I work 2 jobs just to stay afloat. The boy's care is expensive. my ex-husband is a teacher, so he has been ordered to pay a small amount of child support a month, but it really doesn't go far.He started dating his girlfriend a year ago. She's a doctor in her early thirties, and wants to move across the country to be close to her family. My husband told me he wants to do the same. I told him that I wouldn't let the kids go move across the country, and he admitted he didn't want them to. He told me that he will pay more child support but he is "done". I had a panic attack when he told me that. I can't do this alone. The every other week I don't have them is the happiest time. I'm not constantly on alert and housebound. I can go out and spend at least a little time on me in between my jobs.What can I do? Can I prevent this? I'm in shock. via /r/Parenting https://ift.tt/375FAxg